Antimicrobial Resistance Pattern and Genetic Characteristics of ESBL and Carbapenemase-producing Escherichia coli at a Tertiary Care Hospital in Bangladesh.

Uropathogenic Escherichia coli is frequently resistant to different antibiotic leading to a critical condition of the patients. The purpose of the present study was to see antibiotic resistance pattern and genetic characteristics of ESBL and Carbapenemase-producing Escherichia coli. This cross sectional study was conducted in the Department of Microbiology at Mymensingh Medical College, Mymensingh, Bangladesh from October 2014 to December 2015. Patients presented with clinically diagnosed urinary tract infection at any age with both sexes who attended in the OPD of Mymensingh Medical College Hospital and the Doctors Diagnostic Centre in Mymensingh, Bangladesh was selected as study population. Non duplicate clinical isolates from urine were collected in full aseptic precaution for culture of bacteria. Escherichia coli were confirmed by PCR Stargetingadk. Antimicrobial susceptibility was measured by broth microdilution test. Minimum inhibitory concentrations against 18 antimicrobial agents were measured. Beta-lactamase genes were detected by multiplex PCR. For all the isolates showing resistance to imipenem and/or meropenem, presence of carbapenemase genes was confirmed by multiplex/uniplex PCR using primers. A total of 233 non-duplicate clinical isolates of Escherichia coli were collected from patients of which dominant phylogenetic group was B2 which was 78(33.5%) isolates of which 71 isolates were B2a and 7 isolates were B2b. Furthermore, Group A was in 29.6% isolates and Group D was in 26.6% isolates. E. coli showed significantly higher resistance rates to piperacillin, cephalosporins, and some other antimicrobials. Meropenem-resistance was detected in 8.2% of E. coli. The detection rate of blaTEM was 41.6% in E. coli. Carbapenemase genes were detected in 9(3.9%) isolates of E. coli and identified as genes encoding NDM-1, -5, and 7 and OXA-181. All the blaNDM-positive E. coli isolates carried also blaCTX-M-15, except for a group B1 isolate. E. coli is significantly higher resistance rates to piperacillin, cephalosporins, and some other antimicrobials and possesses different ESBL and carbapenemase genes.